Analysis of threshold dynamics of epidemic models in a periodic environment

Download
2013
Evcin, Cansu
Threshold dynamics used to control the spread of the disease in infectious disease phenomena has an overwhelming importance and interest in mathematical epidemiology. One of the famous threshold quantity is known to be the basic reproduction ratio. Its formulation as well as computation is the main concern of infectious diseases. The aim of this thesis is to analyze the basic reproduction ratio in both autonomous and periodic systems via defining R0 as the spectral radius of the next generation operator. This thesis presents the vector host model for the diseases Dengue fever and avian influenza. As emerging of the diseases shows periodicity, systems of periodic ordinary differential equations are considered for both types of diseases. Simple implementation of the time-averaged systems gives rise to the comparison of these with the periodic systems. Thus, we investigate the occurence of the existence of underestimation or overestimation of the basic reproduction ratio in timeaveraged systems.

Suggestions

INVESTIGATION OF EFFECTS OF VITAMIN D AND VITAMIN D METABOLIZING CYP450 ISOZYMES ON MULTIPLE SCLEROSIS PATHOPHYSIOLOGY IN ANIMAL MODEL BY MOLECULAR APPROACHES
Evin, Emre; Adalı, Orhan; Department of Biology (2021-8)
Multiple sclerosis (MS) is a complicated, recurrent, and often progressive inflammatory demyelinating autoimmune disease of the central nervous system, yet etiopathogenesis remains unsolved. MS frequency increases with increasing latitude, leading to a hypothesis that MS is inversely correlated with the duration and intensity of sunlight and vitamin D concentrations. In this study, the relationships between vitamin D supplementation, MS, VDR, and vitamin D metabolizing CYP enzymes, including CYP2R1, CYP27A1...
ANALYSIS OF NEUROONCOLOGICAL DATA TO PREDICT SUCCESS OF OPERATION THROUGH CLASSIFICATION
Bagherzadi, Negin; BÖRCEK, ALP ÖZGÜN; TOKDEMİR, GÜL; ÇAĞILTAY, NERGİZ; MARAŞ, HADİ HAKAN (2016-10-05)
Data mining algorithms have been applied in various fields of medicine to get insights about diagnosis and treatment of certain diseases. This gives rise to more research on personalized medicine as patient data can be utilized to predict outcomes of certain treatment procedures. Accordingly, this study aims to create a model to provide decision support for surgeons in Neurooncology surgery. For this purpose, we have analyzed clinical pathology records of Neurooncology patients through various classificatio...
Evaluation of methylation profiles of an epidermal growth factor receptor gene in a head and neck squamous cell carcinoma patient group
Mutlu, M.; Mutlu, Pelin; Azarkan, S.; Baylr, Ö.; Öcal, B.; Saylam, G.; KORKMAZ, MEHMET HAKAN (2021-03-23)
Upregulation of the epidermal growth factor receptor (EGFR) gene has shown an important impact on the development of head and neck cancers due to its important regulation role on multiple cell signaling pathways. The aim of this study was to investigate the methylation pattern of the promoter region of the EGFR gene between head and neck squamous cell carcinoma (HNSCC) patients and a control group. Forty-seven unrelated HNSCC patients, clinically diagnosed at the Department of Otorhinolaryngology, Dlşkapl Y...
Model comparison for gynecological cancer datasets and selection of threshold value
Bahçivancı, Başak; Purutçuoğlu Gazi, Vilda; Department of Statistics (2019)
Cancer is a very common system’s disease with its structural and functional complexities caused by high dimension and serious correlation of genes as well as sparsity of gene interactions. Hereby, different mathematical models have been suggested in the literature to unravel these challenges. Among many alternates, in this study we use the Gaussian graphical model, Gaussian copula graphical model and loop-based multivariate adaptive regression splines with/without interaction models due to their advantages ...
A test for detecting etiologic heterogeneity in epidemiological studies
Karagulle, S.; Kalaylıoğlu Akyıldız, Zeynep Işıl (2016-02-17)
Current statistical methods for analyzing epidemiological data with disease subtype information allow us to acquire knowledge not only for risk factor-disease subtype association but also, on a more profound account, heterogeneity in these associations by multiple disease characteristics (so-called etiologic heterogeneity of the disease). Current interest, particularly in cancer epidemiology, lies in obtaining a valid p-value for testing the hypothesis whether a particular cancer is etiologically heterogene...
Citation Formats
C. Evcin, “Analysis of threshold dynamics of epidemic models in a periodic environment,” M.S. - Master of Science, Middle East Technical University, 2013.